Dr. Ashok Gopalarathnam is an associate professor of mechanical & aerospace engineering at NCSU. As a boy he read adventure novels about a detective in Special Air Police. Today he uses wind tunnels and computer simulations to understand the physics of vortices and stalls of airplanes, helicopters, and hand-held drones.
When did you discover you wanted to be an aeronautical engineer?
I have always been fascinated with airplanes and flying. As a boy, I read adventure novels about an Indian-born British gentleman Biggles—the nickname of James Bigglesworth—a flying intelligence officer and member of the Special Air Police. I loved math and physics so I was fortunate to make the cut and get into to the Indian Institute of Technology in Madras (IIT).
What did you study in college?
I started my college career in aeronautical engineering. About a year and a half into the aeronautical engineering program at IIT, I picked up an old issue of National Geographic that had an article about do-it-yourself ultra light aircraft. We didn’t have those in India at the time. The whole idea of being able to design, build, and fly a plane out of aluminum tubes, Dacron cloth, and a small engine captured my imagination. I convinced a couple of classmates to join me in designing and making one for a Senior Design Project. This was pre-internet, remember. We were very naive about the skills and knowledge that are required for designing an aircraft from scratch. We made multiple iterations of our ideas on paper and tested an engine but didn’t get a flying machine up in the air in one year. But I got hooked. I decided to stay and get a Master’s degree to try and finish it, but an opportunity came knocking. Instead, my classmate and I were invited by the National Aerospace Laboratories (NAL) in Bangalore. They asked us to join their team to design and build the first all-composite airplane in India. Four years later we had an airplane, named the Hansa-2, ready for flight-testing. By this time I had taken flying lessons and obtained a private pilot’s license. After the initial test flights were completed, I was able to go up in the Hansa with the test pilot. What a thrill! I achieved the dream I had imagined when reading that National Geographic article six years back.
Where did your career take you?
It turned out that I was able to finish my Master’s while working at NAL. This is where I discovered that I liked the research. At every stage of the project there were questions that needed answers. We created a 1/5-scale model and tested it in a subsonic wind tunnel to measure the forces, look for the eddies and vortices that cause abnormal flight and stalling. We put oil coating on the wings to visualize the air patterns that emerged. These patterns told us if the flow around the wing was attached or separated. Separated flow leads to a stall. When the wings stall, the airplane can go out of control. I wanted to understand how and why, and what could be done to prevent it. I decided to study for my PhD at University of Illinois at Urbana Champaign with Michael Selig. We worked on low speed aerodynamics for the design of airfoils and car wings. We were funded by Ford Motor Company to improve the down force on a racecar wing design, which increases the friction between the ground and the tires of the Formula 1 and the Indy cars so that they hug the ground when they turn their corners. A highlight of that time in my career was a summer I spent in Mojave, California, working on airfoil and wing design for the aircraft designer and private space flight pioneer Burt Rutan.
What do you like about your job today?
Today, I am an Associate Professor of Aerospace Engineering at NCSU. I do research for the U.S. Air Force Office of Scientific Research, the Army Research Office, the NASA Langley Research Center, and the industry. I am researching the vortices that are caused by flapping flight—what insects and birds do—so that it can be applied to hand held drones. I am studying the unsteady flight of the helicopter rotor blades to develop a prediction method. I am studying the aerodynamics of wing stall so that we can model this in real time for use in flight simulators to train future pilots in stall prevention and recovery.
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